<template>
  <div>
    <p>请选择你要购买的书籍</p>
    <ul v-for="(item,index) in arr" :key="index">
      <li>{{item.name}}</li>
      <button @click.prevent="add(index)">买书</button>
    </ul>
    <table border="1" width="500" cellspacing="0">
      <tr>
        <th>序号</th>
        <th>书名</th>
        <th>单价</th>
        <th>数量</th>
        <th>合计</th>
      </tr>
      <tbody v-for="(item,index) in arr " :key="index">
        <td>{{index+1}}</td>
        <td>{{item.name}}</td>
        <td>{{item.price}}</td>
        <td>{{item.count}}</td>
        <td>{{item.price * item.count}}</td>
      </tbody>
    </table>
    <p>总价格为:{{sumtotal}} </p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      sumtotal:0,
      arr: [
        {
          name: "水浒传",
          price: 107,
          count: 0,
        },
        {
          name: "西游记",
          price: 192,
          count: 0,
        },
        {
          name: "三国演义",
          price: 219,
          count: 0,
        },
        {
          name: "红楼梦",
          price: 178,
          count: 0,
        },
      ],
    };
  },
  methods:{
    add(index){
      this.arr[index].count++
      this.sumtotal += this.arr[index].price
    }
  }
};
</script>